Malate dehydrogenase of a mosquito, Culex p. quinquefasciatus: developmental changes, polymorphism, and physicochemical characterization. Malate dehydrogenase (MDH) of larval, pupal, and adult stages of Culex p. quinquefasciatus has been characterized by electrophoresis, isoelectric focusing, and other physicochemical means. It exists as a multiple molecular form possessing a large number of isoenzymes, from a minimum of three in early instar larvae to as many as 14 in adults. The isoenzyme pattern changes during development with respect to both relative activity and the appearance of some new forms and disappearance of others. Each developmental stage possesses a characteristic electrophoretic and gel isoelectric focusing pattern. MDH isoenzymes differ in their response to heat and thiol reagents. Similar electrophoretic variants from larvae, pupae, and adults show great differences in their response to heat treatment at 50 C and 56 C, indicating some differentiation of isoenzymes in each stage of development. Homogenization of whole mosquitos in mercaptoethanol solution results in a sharp increase in the activity of the principal bands and a decrease or disappearance of minor ones. The possibility of some minor bands being "conformers" arising due to nongenetic factors is discussed.


The influence of temperature and calcium on the degree of stretch-activation in isolated K-depolarized vascular smooth muscle strips. Stretching of K-depolarized contracted helically cut strips of pig coronary arteries produced a delayed increase in tension. The influence of temperature and extracellular calcium on this active response to stretch was investigated. Reference for all tension values was the amplitude of contraction (induced by K-depolarization) starting from the high resting tension. 1. The mean amplitude of the delayed tension increase after stretch amounted to 27.5 plus or minus 4.8% (x plus or minus SEM, n equals 9); lowering the bath temperature from 37 degrees C to 27 degrees C caused a drop to 10.8 plus or minus 1.5% (n equals 9; P smaller than 0.0025); increasing the calcium concentration of the bath solution from 2.7 to 6.9 mM produced negligible effects on both the amplitude of the delayed tension increase (24.6 plus or minus 1.0%; n equals 9), and the amplitude of contraction after depolarization. 2. The peak tension time of the active response to stretch was not changed by the 6.9 mM calcium, but prolonged from 27.9 plus or minus 4.0 to 40.7 plus or minus 4.4 minutes (P smaller than 0.025) by lowering the bath temperature to 27 degrees C. At the high calcium level the preparation contracted faster after depolarization than at the normal calcium level. 3. The experimental results correspond with the conception of the sliding filament mechanism as the basic process of contraction also in vascular smooth muscle preparations. The delayed tension increase after stretch may be caused by a recruitment of interaction sites between contractile proteins.


Pathogenic implications of age of onset in juvenile rheumatoid arthritis. An analysis of age of onset in juvenile rheumatoid arthritis was performed in the last 300 children seen in our clinic. There was a peak age of onset in girls at 1 to 3 years. Distribution of age of onset in boys was bimodal with the first peak at 2 years of age and the second at 9 years. There was no accentuation of frequency in either sex in the 10- to 14-year age group. The distribution of age of onset was bimodal in both monarticular and polyarticular onset of disease, but no particular modal age of onset was seen with systemic onset of disease. It is possible that these data reflect that JRA is not a homogenous disease, or that there are age-sex related differences in host susceptibility or pathogenic agents.


Connective tissue response to immobility. Correlative study of biomechanical and biochemical measurements of normal and immobilized rabbit knees. The biomechanical changes in rabbit knee contractures were measured after 9 weeks of immobilization. These results were correlated with the biochemical composition of periarticular connective knee tissue of the same knees. The loss of total hexosamine correlates significantly with joint stiffness on an animal-to-animal basis. Total hexosamine also correlates with the energy required cyclicly to flex and to extend the experimental joints. Of the individual glycosaminoglycan fractions, only hyaluronic acid showed significant correlation with the biomechanical data. The possible mechanism of contracture formation was postulated based on these results.


Histochemical and electron microscopic comparison of tissue produced by rabbit articular chondrocytes in vivo and in vitro. Rabbit articular chondrocytes produce a chondroid matrix in subculture. This tissue was compared to articular cartilage by histochemical and electron microscopic techniques. Although both tissues were similar, the cytology of chondrocytes and the matrix structure of chondroid tissue appeared less mature.


Double outlet right ventricle with 1-malposition of the aorta. Four patients are described with a recently recognized variant of double outlet right ventricle. Clinical examination favoured tetralogy of Fallot, but the chest X-ray suggested corrected transposition. Catheterization and angiocardiography showed that the aorta was to the left of the main pulmonary artery, and both arose from a normally positioned morphological right ventricle. Egress of blood from the left ventricle was through a subaortic ventricular septal defect. In all patients severe pulmonary stenosis was present and the right coronary artery ran an anomalous course anterior to the pulmonary valve ring. Two children had successful total correction, and one a palliative Blalock-Taussing shunt. Necropsy material from the fourth patient allowed confirmation of the ventricular morphology and the conducting tissued was examined. In corrective surgery, blood from the left ventricle was rerouted into the aorta by an intraventricular baffle. Pulmonary stenosis was relived by infundibulectomy and outflow tract patch.


Inferior myocardial infarction and right coronary artery occlusive disease. A correlative study. The present study represents an attempt to correlate the electrocardiogram and coronary arteriogram in patients with an inferior transmural infarct - or total occlusion of the right coronary artery. The influence of the collateral circulation on these findings was also evaluated. Fifty patients with a total occlusion of the right coronary artery had characteristic electrocardiographic changes of an inferior infarct in 44 per cent, very suspicious changes in 32 per cent, and no changes suggesting an inferior infarct in 24 per cent. However, in this latter group who had no evidence of an inferior infarct, we were able to recognize a small number who showed an anterior wall infarct. Collateral circulation was more frequently present and more extensive in those patients whose electrocardiograms did not show changes typical of inferior transmural infarction. This suggested that collateral circulation might minimize some of the electrocardiographic abnormalities which would normally result from occlusive disease of the right coronary artery. Another 50 patients, selected because of definite electrocardiographic evidence of typical inferior transmural infarction, were evaluated by coronary arteriography. Severe obstructive disease of the right coronary artery was present in 86 per cent of the group. In the remaining 7 patients (14 per cent) minimal or no disease was found. Infarction of the inferior wall may have resulted from occlusive disease of the anterior descending artery or have been the result of a right coronary artery occlusion with subsequent recanalization. We conclude from our study that a careful analysis of electrocardiographic abnormalities in theinferior leads will, with certain limitations, permit us to estimate the likelihood of a severe lesion in the right coronary artery, and, in the face of definite electrocardiographic evidence of an inferior infarct, to predict the diseased artery.


Acute inferior wall myocardial infarction associated with complete atrioventricular block and left posterior hemiblock. Three cases of acute inferior wall myocardial infarction associated with complete atrioventricular block and junctional escape rhythm showing left posterior hemiblock are presented. The triad appears to consitiute a distinct syndrome. It is postuated that the subsidiary pacemaker is situated either in the bundle of His or the proximal part of the anterior division of the left bundle-branch.


Transient coagulation abnormalities after incompatible blood transfusion. This report describes an unusual hemolytic transfusion reaction. A group O donor was inadvertently transfused with 100 ml of group A red cells during the course of plasmapheresis. Granulocytopenia, thrombocytopenia, hypofibrinogenemia and low levels of factors V, VIII, and IX developed immediately after the infusion. The levels of the cellular elements and coagulation proteins returned to normal in less than an hour; too rapid for a de novo synthesis after consumption of coagulation proteins. We postulate that activation of the kinin system was responsible for the phenomena rather than intravascular coagulation with secondary fibrinolysis.


Successful aortic valve  replacement for aortic regurgitation associated with osteogenesis imperfecta. The occurrence of severe aortic regurgitation in two patients with typical findings of osteogenesis imperfecta is described. Both patients manifested severe haemodynamic abnormalities and underwent successful aortic valve replacement. The operative and pathological findings are discussed.


Acute circulatory effects of dopamine in patients with pulmonary hypertension. Twenty-one patients, 11 with normal pulomonary artery pressures and 10 with pulmonary hypertension,  had haemodynamic measurements performed before and during dopamine infusion while undergoing cardiac catheterization, in order to evaluate the circulatory effects of dopamine in pulmonary hypertension. In both groups on average, heart rate, pulmonary artery mean pressure, aortic mean pressure, and cardiac index increased significantly, while systemic vascular resistance fell significantly during dopamine administration. In neither group did the average pulmonary vascular resistance or right ventricular end-diastolic pressure change significantly. We  conclude that dopamine is a safe and potentially useful drug for the treatment of reduced cardiac output, even in patients with pulmonary hypertension.


Myocardial infarction in young men. Study of risk factors in nine countries. In order to determine whether the development of myocardial infarction in different countries is associated with different risk factors, 240 male survivors, aged 40 or less, were studied in nine countries. In the seven centres in developed countries (Auckland, Melbourne, Los Angles/Atlanta, Cape Town, Tel Avic, Heidelberg, and Edinburgh) there was a high procedure of risk factors, particularly of hyperlipidaemia and cigarette smoking. The prevalence of hypertension, obesity, hyperglycaemia, and hyperuricaemia varied from centre to centre. Risk factors were less prevalent in Bombay and Singapore: the most common risks operating in Bombay seemed to be cigarette smoking and hyperglycaemia, while in Singpore cigarette smoking was the commonest. The mean age of the whole group was 35.4 years. Serum cholesterol levels of 7.25 mmol/l (280 mg/dl) or more were present in 25 per cent of all patients, serum triglyceride levels of 2.26 mmol/l )l200 mg/dl) or more in 35 per cent. 80 per cent of the patients were smokers, and 15 per cent were either for hypertension before myocardial infarction or had a raised blood pressure after myocardial infarction. Obesity was found in 19 per cent of all patients and serum uric acid levels over 0.5 mmol/l (8.5 mg/dl) in 17 per cent. 10 per cent of all patients were either treated for diabetes mellitus before myocardial infarction or showed an abnormal glucose tolerance after myocardial infarction. This collaborative study may help, by showing differences in the prevalence of risk factors, to indicate to each centre and to national and to international organizations, the direction for their future studies into the causation and prevention of myocardial infarction in young men.


Measurement of diastolic closure rate  of normal mitral valve. Published values for the diastolic closure rate of the normalmitral vary and reflect diffference in methods of recording and measurement. From strip chart records it was concluded that the form of the recorded mitral diastolic closure slope can vary, that reproducible measurements of the closure rate can be made from echograms in which diastolic  closure approximates closely to a monophasic form, that the amplitude of  these echograms is maximal, and that their closure movements remain essentially monophasic at chart speeds up to 100 mm/s. Measuring only complexes with essentially monophasic closure movements, the within and between-subjected variation of the normal mitral diastolic closure rate was investigated. The ranges obtained from multiple measurements in a single subject and from a group of 45 normal subjects were comparable  but the distribution of the results differed. It was concluded that there was a real between-subject variation in the normal mitral diastolic closure rate and that the diastolic closure rate in a single subject should be determined by measurement of a series of complexes. The accuracy of measurement of the diastolic closure rate of the normal mitral valve has been improved by using strip chart records and by measuring only echograms in which diastolic closure approximates closely to a monophasic form.


Haemodynamic events in right and left ventricle during angina induced by atrial pacing. Atrial pacing to the point  of angina or up to a maximum rate of 166/min was carried out in 37 patients during coronary angiography. In 9 patients with normal coronary arteries both the right and left ventricular end-diastolic pressures fell remained steady with increasing heart rate. The same response was observed in 14 patients with angiographically proven coronary artery disease. In the remaining 14 patients with provencoronary artery disease the end-diastolic pressure in the left ventricle rose at the point when the patient experienced angina. In 10 of this latter group  there was a simultaneous rise in the right ventricular end-diastolic pressure. In 4 patients the rise in end-distolic pressure was seen in the left ventricle only. The haemodynamic events in the right ventricle during angina appeared in most cases to  mimic the events occurring in the left ventricle. There was no correlation between the angiographic findings and the changes in end-diastolic pressure in the two ventricles during angina.


New performed catheter for entry into pulmonary artery in complete transposition of great arteries. A new performed, semi-rigid, polyethylene catheter, with built-in torque control, has been devised for entry to the pulmonary artery in complete transposition of the great arteries. It has been used 19 times in 17 patients: 18 times the pulmonary artery was entered from the right atrium (via the left atrium and ventricle) in a time between 40 s and 15 min (median 5 min); the patients' ages were 2 days to 6 years (median 8 months) and their weights were 3.1 to 13.3 kg (median 6.9 (kg: in the remaining 1 day-old patient, the procedures was terminated because of atrial flutter. The catheter was introduced into the axillary vein in  3 patients and thesaphenous or femoral vein in the remainder. It is suitable for angiocardiography, and the other heart chambers and vessels were easily entered. Thus the catheter has certain advantages over previously described methods for entry to the pulmonary artery, particularly when there is inferior vena caval thrombosis, or when angiocardiography is necessary. Its use does depend on the presence of an interatrial communication, so a method for entry to the pulmonary artery by retrograde catheterization from the axillary artery using a different catheter is also presented; this was successful in 2 patients with ventriculal sepatal defect.


Treatment with digoxin and measurement of serum digoxin levels after myocardial infarction. Forty-nine patients admitted to a Coronary Care Unit with myocardial infarction complicated by left ventricular failure, were treated with 1.75 mg Lanoxin over 36 hours. Serum digoxin levels were measured by radioimmunoassay at 8, 24, and 48 hours. No difference in serum levels was observed between those patients who received 'old' (reduced bioavailability) and those who received 'new' Lanoxin. Serum levels were significantly higher at 8 and 24 hours in those patients who received their first dose intramuscularly compared with those who received their first dose orally, irrespective of the bioavailability of the oral preparation used. No correlation was observed between serum digoxin levels and serum urea or creatinine during the 48-hour period of study. The incidence of arrhythmias is reported, but no conclusion can be drawn as to whether or not the glycoside contributed to this in any way. The use of digoxin in patients with acute myocardial infarction complicated by left ventricular failure is justifiable in the light of available evidence. However, in view of the possible predisposition of such patients to toxicity, lower serum levels than were achieved in many of our patients seem desirable and a modified dosage schedule is suggested.


Löffler's endocarditis.

Löffler's endocarditis. The clinical, laboratory, and necropsy findings in a patient with massive eosinophilia and fatal cardiac failure are reported. Necropsy revealed partial obliteration of the lumen of the left ventricle with dense white thrombus, and fibrous infiltration of the myocardium. An additional finding, not hitherto described in Löffler's endocarditis, was massive enlargement of the mesenteric lymph nodes.


Atrial dissociation.

Atrial dissociation. A case of transient atrial dissociation developing in a woman with acute myocardial infraction is presented. The mechanism of this condition and its  differentiation from other conditions which may mimic it  are discussed.


Left anterior hemiblock masking inferior myocardial infarction. A case is presented in which transient left anterior hemiblock masked the electrocardiographic signs of old inferior wall infarction. The electrocardiographic features are correlated with the anatomopathological findings. This case re-emphasizes the need for careful evaluation of patients with chest pain and left anterior hemiblock.


Antepartum diagnosis of the "terminal" fetal state by cardiotocography. Since 1969 it has been the policy of this department to perform regular cardiotocograms on all patients admitted during the antenatal period for severe hypertension, with or without proteinuria, and on those in whom poor intrauterine fetal growth was suspected. In five such patients where the fetus died in utero, beat-to-beat variation was reduced and late decelerations were observed. In a further twelve patients similar changes made delivery by elective Caesarean section appear advisable. Half of the infants so delivered had severe metabolic acidosis at birth.


The effect of pregnancy on the renal handling of glucose. Tubular reabsorption of glucose has been measured during glucose infusion in 29 healthy women during and after pregnancy. All the women had normal glucose tolerance to an oral load, and normal glucose excretion when not pregnant, but exhibited a wide range of daily glucose excretion in pregnancy. Throughout pregnancy the renal reabsorption of glucose is less effective than in the non-pregnant state and, in general, the greater the amount fo glycosuria which develops in pregnancy, the less effective is the reabsorption during infusion. Post partum, women with minor degrees of glycosuria during the preceding pregnancy return to a normal highly efficient reabsorption performance during infusion, but women who exhibit greater degrees of glycosuria have a reduced capacity to reabsorb even though they are no longer glycosuric after the pregnancy. It is concluded that pregnancy imposes some specific change in the glucose reabsorptive capacity of the proximal tubule and that women with more than usual degrees of glycosuria in pregnancy may, in addition, have an element of tubular damage. This is discussed in relation to other renal function changes in pregnancy in an attempt to explain the characteristic intermittency of clinical glycosuria in pregnancy.


Fetal death in eclampsia: I. Its relation to low gestational age, retarded fetal growth and low birthweight. Of 173 eclamptics admitted to the only public maternity hospital in Cali, Colombia 44 had stillbirths making a rate of 25-4 per cent. Fetuses delivered before 32 weeks had nearly four times the stillbirth rate of those delivered at term. Those weighing less than 1600 g. had stillbirth rates about six times higher than those weighing above 2500 g. An attempt was made to divide the risk conveyed by low birthweight into two components; that which was due to low gestational age, and that which was due to an abnormally low rate of growth during the gestational time available. Deviation of birthweight below that expected for age (retarded fetal growth, RFG) was used as a measure of the latter component. RFG became more common as gestation progressed and was associated with fetal death only in the latter part of gestation and with marginal statistical significance. After 35 weeks, fetuses at or below two standard deviations from Gruenwald's mean weight for gestational age (Gruenwald, 1966) had a fetal death rate five times higher than those at the mean. The risk of fetal (intrauterine) death conveyed by low gestational age has not been definitively explained. Alternative pathophysiological mechanisms are discussed.


Fetal death in eclampsia: II. The effect of non-therapeutic factors. The ability of 15 variables to predict fetal death is examined among 173 eclamptic women admitted to the only public maternity hospital in Cali, Colombia, between 1st Janurary 1964 and 31st December 1970. In addition to low gestational age and retarded fetal growth, high systolic pressure and the unmarried status carried excess risk. Primiparae appeared to be of lower risk because their eclampsia tended to occur late in gestation and was characterized by less retarded fetal growth. Older women and women with a history of abortion appeared to be of higher risk because they tended to have higher systolic pressures. A discriminant function risk formula is presented which generated groups with a nine-fold difference in fetal death rates. This formula could be used to standardize for relevant non-therapeutic factors which meant vary between patient groups who had received different therapeutic regimens.


Hormonal responses to a first course of clomiphene citrate in women with amenorrhoea. The hormonal criteria of a "normal" or "ovulatory" response, and three grades of subnormal anovulatory responses, were defined during a first course of treatment with clomiphene citrate in twenty patients with amenorrhoea for which no organic cause could be found. The hormonal responses were estimated by frequent serum measurements and by the menstrual response. Seven patients had a normal or ovulatory response with a late rise of serum progesterone and subsequent menses. Their serum luteinizing hormone (LH) and oestradiol (E2) responses were greater than in spontaneous menstrual cycles. Five patients gave only partial responses, with menstruation and no prior rise of progesterone, Their serum LH and E2 responses were generally lower than in the normal group but had the same pattern except for an absence of the luteal phase rise in E2. Five patients who did not menstruate showed smaller and more variable responses. The remaining five showed no hormonal responses. The second and third groups had ovulatory responses on subsequent clomiphene courses, whereas no improvement was shown by the last group. The serum E2 responses offered the most sensitive index of the responsiveness to clomiphene. Response values in our normal group suggested that higher progesterone levels need to be reached after clomiphene administration than in spontaneous cycles for ovulation to be inferred. The serum prolactin showed no consistent response during the clomiphene test; three patients with moderately raised basal prolactin levels had "normal" responses.


Endometrioid tumours of the ovary.

Endometrioid tumours of the ovary. From 291 cases of malignanat disease of the ovary in the North East Metropolitan Region of London, 250 have been classified as of epithelial origin. Of these, 44 have been designated as endometrioid carcinoma. The recognition and features of endometrioid ovarian carcinoma are discussed.


Replacement hormone therapy in gonadal dysgenesis. Curettage carried out during the third week of treatment of ethinyl oestradiol in 14 patients with gonadal dysgenesis showed cystic glandular hyperplasia in seven patients developed a large endometrial polyp and in one atypical changes were found in the hyperplastic endometrium. In seven patients treated by an oestrogen-progestogen combination normal secretory endometrium was seen in five, proliferative change only in one (thought to be due to incorrect timing of the curettage) and a small proliferative polyp in association with secretory endometrium elsewhere in the uterus in the seventh. In view of these changes and report of adenocarcinoma of the endometrium in patients with gonadal dysgenesis treated with oestrogens alone it is suggested that a regime of low dose oestrogen therapy for 21 days accompanied by a progestogen on days 15 to 21 is preferable to oestrogens alone.


Oestrogen-induced endometrial carcinoma in a patient with gonadal dysgenesis. This case report describes the genesis of endometrial carcinoma after prolonged stilboestrol therapy in a patient with gonadal dysgenesis (Turner's syndrome). The varied histological appearance included the presence of cartilage-like material. A review of the literature reveals the need to treat these patients with combined oestrogen/progestogen preparations rather than with continuous unopposed oestrogens.


Endometrial carcinoma after cyclical oestrogen-progestogen therapy for Turner's syndrome. A case of endometrial adenocarcinoma in a patient with Turner's syndrome who had received long term combined oestrogen-progestogen therapy is described.


Topical oestrogen therapy for labial adhesions in children. Labial adhesions separated spontaneously after one month of the topical oestrogen therapy in 22 (88 per cent) out of 25 children. This treatment was safe, painless, without significant complications and of lasting value.


Phaeochromocytoma in pregnancy. Case report. A patient was found to have a phaeochromocytoma in the 36th week of pregnancy. She was successfully managed by medical treatment, vaginal delivery and resection of the adrenal tumour seven weeks after delivery.


Enrichment of rat tissue lipids with fatty acids that are prostaglandin precursors. The effects of supplementation of a complete diet with ethyl arachidonate and with ethyl dihomo-gamma-linolenate (20 : 3Omega6) on the fatty acid composition of plasma and tissue lipid classes were studied in normal rats. 2. These prostaglandin precursors were incorporated in varying degrees into all lipid  classes of the tissues that were investigated. The largest elevations were seen in plasma and tissue triacylglycerols. Significant increases were also observed in phospholipids, cholesteryl esters and the free fatty acid fraction. 3. Following the feeding of the ester of 20 : 3Omega6, arachiodonate levels also rose in the lipids of some tissues. In others, such as the renal medulla and platelets, and increase in 20 : 3Omega6 content occurred without a rise in 20 : 4. 4. Platelet aggregation is known to be stimulated by 20 : 4 (via active metabolites), but not by 20 : 3Omega6. The ability to modify 20 : 3Omega6 levels selectively in certain tissues is of interest in light of such pharmacologic differences from 20 : 4.


The effect of essential fatty acid deficiency upon fatty acid uptake by the brain. Young adult rats, either control or essential fatty acid deficient, were administered either [3-H] oleic acid or [3-H] arachidonic acid by stomach tube. In addition, a group of control rats was given [3-H] palmitic acid. The rats were killed at various times therafter, and the radioactivity of the lipids of brain and plasma was examined. In confirmation of previous work, the blood lipid label was found to rise rapidly and then fall, wheras the activity of brain lipids increased slowly and did not show a decline through the 24-h period studied. Analysis of the brain uptake data according to first-order kinetics confirmed the impressions gained from visual inspection of the data. The initial rate of uptake of arachidonic acid was about 4.5 times that of oleic acid in control animals and in deficient animals. Essential fatty acid deficiency, however, did not induce an altered rate of uptake for either oleic acid or arachidonic acid. The rate of uptake of palmitic acid by control rats was not significantly different from that of oleic acid. Even though the initial rates of incorporation of oleic and arachidonic acids were not changed during essential fatty acid deficiency, the final levels of radioactivity obtained in brain lipids were higher in deficient rats with both fatty acids. The plateau value obtained with oleic acid was 1.5 times higher in deficient animals, while the plateau value for arachidonic acid was 1.7 times higher. An experiment in which deficient animals were allowed access to a control diet for 12 or 24 h prior to the labeling experiment suggested that the higher levels of radioactivity found in brain lipids of deficient animals was not due to an isotope dilution effect. Such animals still displayed the labeling pattern of deficient animals with arachidonic acid, while the results with oleic acid varied somewhat. Our results suggest that essential fatty acid deficiency does not alter the ability of the brain to take up the fatty acids studied. However, the fatty acids, especially arachidonic, are retained in the brain to a greater extent in the deficient animals.


The structure and distribution of ceramide aminoethylphosphonates in the oyster (Ostrea gigas). 1. Ceramide aminoethylphosphonate was isolated from the adductor, gills, mantle and viscera of oysters. 2. After drastic acid hydrolysis of the lipid, aminoethylphosphonic acid was the only water-soluble carbon-phosphorous compound detected. 3. The main fatty acids of ceramide aminoethylphosphonates were hexadecanoic acid (77-90%) and 2-hydroxy hexadecanoic acid (13-15%). 4. Hexadeca-4-sphingenine, octadeca-4-sphingenine and octadeca-4,8-sphingadienine were identified as the major long chain base components. However, the ratio of the three bases was characteristic for each tissue; the adductor muscle contains primarily hexadeca-4-sphingenine, and the viscera, octadeca-4,8-sphingadienine. The gills and mantle contain the three bases in approximately equal concentration. 5. The main molecular species in the adductor muscle was hexadecanoyl-hexadeca-4-sphingenyl 2-aminoethylphosphonate, while in the viscera hexade-canoyl-octadeca-4,8-sphingenyl 2-aminoethylphosphonate predominated.


Raman spectra and vibrational assignments for dipalmitoyl phosphatidylcholine and structurally related molecules. Raman spectra of dipalmitoyl phosphatidylcholine and structurally related molecules are examined and vibrational transitions assigned for the C-C, phosphate and C-H stretching modes of these molecules. Particular emphasis is placed on the characteristics of the Raman spectra in the 2800-3000, 1000-1150 and 700-800 cm-minus 1 regions. It is found that hydrocarbon transitions dominate the spectra at the expense of those of the phosphate and choline groups. The methyl and methylene C-H stretching assignments have been clarified for the Raman spectra of phospholipid systems.


Sterol balance studies in the rat. Effects of dietary cholesterol and beta-sitosterol on sterol balance and rate-limiting enzymes of sterol metabolism. Sterol balance measurements using isotopic and chromatographic techniques were carried out in rats fed diets containing beta-sitosterol (0.8%) and cholesterol (1.2%). The activities of the rate-limiting enzymes of cholesterol synthesis (beta-hydroxy-beta-methylglutaryl-CoA reductase, EC 1.1.1.34) and bile acid synthesis (cholesterol 7 alpha-hydroxylase) were determined in the same animals. Cholesterol feeding increased cholesterol absorption from 1.2 to 70 mg/day. The increased absorption was compensated for by inhibition of hepatic cholesterol synthesis, enhanced conversion of cholesterol to bile acids (from 13.7 to 27.3 mg/day) and a slight increase in the excretion of endogenous neutral steroids (from 7.7 to 11.2 mg/day). Despite the adaptation there was accumulation of cholesterol in the liver (from 2.2 to 9.2 mg/g). Beta-Sitosterol feeding inhibited cholesterol absorption (calculated absorption was zero). In these rats there was enhanced cholesterol synthesis (from 20.0 to 28.8 mg/day, but no change in the rates of bile acid formation. Measurements of the activities of the rate-limiting enzymes showed fair correlation with cholesterol-bile acid balance. In cholesterol fed animals, beta-hydroxy-beta-methylglutaryl-CoA reductase was inhibited 80% and cholesterol 7 alpha-hydroxylase was enhanced 61%. In beta-sitosterol-fed animals, the reductase was increased 2-fold and cholesterol 7 alpha-hydroxylase was not significantly different from controls.


Diffusion in bile and its implications on detergency. Diffusion coefficients of bile salts, lecithin, and cholesterol above the critical micelle concentration have been measured with the diaphragm cell at varying concentrations of bile salts, lecithin, and added electrolyte. The diffusion of the bile salt can be five times faster than that of the solubilized lipids. This is shown not to be an artifact of multicomponent diffusion, but a result of a different transport mechanism of the bile salt. As a consequence, the concentration of bile salt and lipids at the surface of a cholesterol gallstone can differ from those in the bile solution. The effects of this upon growth and dissolution in detergent solutions are discussed.


Studies on the mechanism of the inhibitory effects of erucylcarnitine in rat heart mitochondria. 1. The mechanism of the inhibitory effect of erucylcarnitine on palmityl-carnitine oxidation in rat heart mitochondria was studied. 2. Erucylcarnitine inhibited in the same time the oxidation of [U-14-C]-palmitylcarnitine and the total rate of oxygen uptake. Other acylcarnitines competed as well for the oxidation with radioactive palmitylcarnitine, but they were well oxidized themselves, so that the total oxygen uptake did not decrease. 3. The presence of erucylcarnitine did not change the distribution pattern of Krebs cycle intermediates derived from [U-minus 14 C] palmitylcarnitine except that succinate/malate ratio increased. 4. The presence of erucylcarnitine did not lead to the formation of any beta-oxidation cycle intermediates from [U-minus 14 C] palymitylcarnitine. The formation of beta-hydroxy-palmityl derivative when rotenon was included into the incubation medium, decreased in the presence of erucylcarnitine. 5. It is postulated, that the inhibited entrance of palmityl groups into the beta-oxidation cycle is due to the fact that erucylcarnitine and palmitylcarnitine behave as substrate-competitive inhibitors for long chain acyl-CoA dehydrogenase. 6. There was observed a latency of 1-2 min in the effect of erucylcarnitine on the palmitylcarnitine oxidation, which seems to correspond to the time required for the formation of high amounts of intramitochondrial erucyl-CoA. 7. Erucylcarnitine inhibited the total oxygen uptake with long, medium and short chain acylcarnitines, pyruvate and alpha-ketoglutarate as substrates, while the oxidation of succinate was not affected. 8. Sequestration of free CoA in the form of very slowly metabolized erucyl-CoA is proposed as the partial explanation of the observed inhibitory effects of erucylcarnitine on the oxidation of CoA-dependent substrates (alternatively to the inhibition at the level of acyl-CoA dehydrogenases in case of acylcarnitines).


The Concanavalin A agglutinating system of cell membranes. The hopes raised by the finding of differential Concanavalin A (Con A) agglutinability of normal and transformed cells in efforts to quantify differences between these cell lines seem not to have been justified.  In this paper, the development of information on the mechanism of action of Con A on the cell surface, as well as the theories put forward at each stage of this development are surveyed.  In this respect, investigations on Con A constitute a case history in biological research.  The involvement of glycoproteins and galactosyltransferases in cell-cell interactions and their relations to Con A are also reviewed.


Sea-blue histiocytosis and beta-thalassemia in the same family. Among 5 families with SBH of Neapolitan origin, herediatry glyco-lipidosis was accompanied in one by beta-thalassemia. All 10 members of this family, namely parents and 8 siblings, were investigated. The mother and two children were found to be carriers of both SBH and beta-thalassemia, while three other siblings were carriers of SBH alone. None of the six patients conformed the classic clinical picture often observed in genotypical SBH. The present state of genotypic transmission of the stigma is discussed on the basis of the author's experience as well as the data in the literature. As for the combination SBH-thalassemia in the same individual it may be concluded that the two genes are most likely independent and certainly not linked.


Cholinergic mechanisms in central thermoregulation in pigeons. 1. In unanaesthetized pigeons the effect on cloacal temperature was studied of acetylcholine (ACh), carbachol, atropine and (+)-tubocurarine injected into a cannulated lateral cerebral ventricle. The experiments were carried out at an ambient temperature of 19-25 degrees C. 2. ACh or carbachol injected intraventricularly produced hyperthermia, and in larger doses hyperthermia followed by hypothermia. These were central effects because they were not obtained when these drugs were injected in the same doses intravenously. 3. Atropine injected intraventricularly produced hypothermia which was greater and longer lasting than the hypothermia produced with the same dose of atropine injected intravenously. After the intraventricular injection of atropine the hyperthermic effects of ACh and of carbachol were abolished. 4. (+)-Tubocurarine injected intraventricularly produced a long-lasting hyperthermia in doses which had no effect on temperature when injected intravenously. After the intraventricular injection of tubocurarine the hypothermic effects of ACh and of carbachol were abolished. 5. It is concluded that the effects of ACh had carbachol imitate the effects of ACh released from cholinergic neurones in the central pathway involved in temperature regulation. The hypothermic effect of atropine is attributed to unmasking the activity of continuously released ACh acting on nicotinic receptors, and the hyperthermic effect of tubocurarine to unmasking the activity of continuously released ACh acting on muscarinic receptors.


Lack of cardiac or bronchodilator tachyphylaxis to isoprenaline in the dog. 1. Tachyphylaxis to heart rate and bronchodilator effects of (plus or minus)-isoprenaline was studied in anaesthetized open-chest dogs by 5 procedures. 2. Heart rate responses to a series of intravenous injections of isoprenaline were essentially unchanged before and after a 15 min infusion of isoprenaline (at 3 doses). 3. Heart rate and bronchodilator responses in the same animal to an intravenous injection of isoprenaline were not significantly different before and after a 30 min infusion of isoprenaline (at 2 doses). 4. Heart rate responses were relatively constant to an isoprenaline injection given every 30 min during a 4 h infusion of isoprenaline (at 3 doses), but the magnitude of the response was smallest for the largest infusion dose (highest background heart rate) and greatest for the smallest infusion dose (lowest background heart rate). 5. Heart rate and bronchodilator responses in the same animal to isoprenaline were relatively constant during a 5 h infusion of isoprenaline (at 2 doses). 6. Bronchodilator responses to intratracheally administered isoprenaline aerosol were essentially unchanged during a 4-5 h period using various doses and procedures. 7. Tachyphylaxis to the heart rate of bronchodilator effects of isoprenaline was not observed. The present data give no support to the hypothesis that tachyphylaxis to isoprenaline aerosols is an important mechanism in asthma mortality.


An investigation of the tachycardia produced by intracerebro-ventricular injections of isoprenaline in mice. 1. Isoprenaline, 3.5-20 ng, injected intracerebroventricularly in atropinized mice under pentobarbitone anaesthesia produced a dose-dependent tachycardia. 2. Pretreatment with either reserpine or pempidine blocked nervously-mediated tachycardia as shown by marked reduction of that due to stimulation of the spinal outflow in pithed mice. After pretreatment with these drugs, intracerebroventricular isoprenaline caused tachycardia of a similar degree and time course to that in mice not so pretreated. 3. Pretreatment with either reserpine or pempidine caused supersensitivity to the tachycardia due to intravenous isoprenaline. 4. When allowance was made for this supersensitivity in the effect of intracerebroventricular isoprenaline in pretreated mice, a small dose-dependent residual effect remained that could be attributed to leakage of isoprenaline into the peripheral circulation. 5. This was confirmed by the appearance of a late-developing tachycardia on intracerebroventricular injection of isoprenaline in spinal mice. 6. It is therefore concluded that the tachycardia caused by intracerebroventricular isoprenaline in mice is, at least initially, of central origin.


Effects of reserpine on the adrenal medulla of the spontaneously hypertensive rat. 1. Reserpine administration resulted in a larger initial decline in adrenal catecholamines in spontaneously hypertensive rats (SHR) than in normotensive Wistar rats (NWR); the difference was eliminated by pretreatment with cholisdondamine. 2. Reserpine also produced a larger increase in SHR catecholamines and dopamine beta-hydroxylase several days later; chlorisondamine pretreatment did not prevent the increases, although it did slightly slow the increases. 3. Vesicles from SHR, or NWR incubated with reserpine in vitro demonstrated equivalent inhibition of adenosine 5'-triphosphate (ATP)-Mg-2+-stimulated adrenaline uptake. 4. Recovery of uptake was more rapid in SHR than in NWR after reserpine inhibition, and this was associated with a burst of new vesicle synthesis in the SHR; chlorisondamine pretreatment reduced the number of new, immature vesicles in reserpine-treated SHR. 5. Both SHR and NWR secreted equal proportions of their adrenal catecholamine contents after nicotine administration. 6. These data suggest that the sympatho-adrenal system of the SHR exhibits an enhanced reflex response to reserpine but that reserpine is equally effective in SHR and NWR in producing blockade of vesicular catecholamine transport; these alterations can affect markedly the actions of autonomic drugs in the SHR.


The irreversible binding of acetylcholine mustard to muscarinic receptors in intestinal smooth muscle of the guinea-pig. 1. Acetylcholine mustard (N-2-chloroethyl-N-methyl-2-acetoxyethylamine), a potent muscarinic agonist, binds virtually irreversibly to muscarinic receptors in longitudinal muscle strips from guinea-pig small intesting, as shown by the inhibition of the binding of E13-H]-propylbenzilycholine mustard ([3-H-PrBCM), an affinity label for the muscarinin receptor. 2. A value for the apparent binding affinity of acetylcholine mustard and a value for the rate constant for the receptor alkylation reaction have been deduced from the rate of onset of the inhibition of [3-H]-PrBCM binding. 3. The kinetic constants obtained may refer largely to the interaction between acetylcholine mustard and the desensitized receptor. 4. At high concentrations acetylcholine mustard practically abolishes the contractile response to carbachol. At the concentrations acetylcholine mustard appears to have multiple actions on the tissue.


Changes of human plasma dopamine-beta-hydroxylase activity after intravenous administration of theophylline. The intravenous administration of theophylline to ten healthy human subjects produced either an increase of circulating plasma dopamine-beta-hydroxylase or no change. The rise of plasma enzyme activity may reflect the increased peripheral catecholamine release induced by theophylline.


Sensitivity of neonatal rabbit ileum to histamine. Segments of ileum from newborn rabbits contracted in response to histamine but sensitivity declined from age 11 days. Intestine from adult animals barely contracted to histamine, even in a concentration of 3 times 10- minus 3 M. Such variation with age was not observed with acetylcholine. The response to histamine was effected by mepyramine-sensitive receptors which appeared to decrease in number as the animals aged.


A test for seasonality of events with a variable population at risk. A statistical significance test to detect seasonality of epidemiological events is described. The method is similar to that of Edwards, but makes it possible to allow for an arbitrary pattern of variation in the population risk, and also for the unequal lengths of time sectors of a cycyle of seasons (e.g., months of a year). From the test it is possible to estimate the amplitude of seasonal variation and the time at which the maximum occurs in a postulated simple harmonic fluctuation; the adequacy of the description of the data by a curve of this kind may be evaluated using a goodness-of-fit test. A numerical example of the calculations is given using some anencephalus data, and the results are compared with those of alternative tests.


Seasonal variation in anencephalus in Canada. A study of the monthly numbers of stillbirths and of deaths due to anencephalus in Canada from 1954 to 1962 showed a weak tendency to a winter excess of affected births. The seasonal trend was more marked in the Prarie provinces and in Quebec than elsewhere; the maximum rate of anencephalus occurrence was in October to December in the Prairies and in British Columbia, and in January to March in other regions.


A 12-year study of menarcheal age.

A 12-year study of menarcheal age. Data on menarcheal age were collected on girls admitted to the University College of Swansea over a 12-year period. It appears that the downward trend in menarcheal age ceased in girls born about 1946 (the 1965 student intake) and that an upward swing may have since occurred. This change in the secular trend is not due to the association of menarcheal age with family size or of position in sibship, or to changes in the regional composition of the student intake. The well established effect of physique remains, but there is no effect of socio-economic status as assessed by the Registrar-General's classification of the father's occupation.


Differential response to recall in a cervical screening programme. Three years after a normal cervical smear, 1,007 women were followed up to see how they responded to a computer-generated recall letter. Seven women had died and 150 had had interim smears (mainly in association with regular contraceptive or postnatal examination). Of the remaining 850, low response was not related to lower social class in the way initial recruitment to screening is. Working outside the home was more obviously associated with lower response, as wass full-time compared with part-time work. Response was also related to where the first smear was taken (61% of women first examined at a local authority clinic, but only 29% of those from a mobile industrial clinic) and was related to repetition of a familial routine which favoured permanent rather than mobile facilities. Interviews with returners and non-returners showed that over 90% remembered receiving recall letters, so non-response was a conscious decision not to attend. When a first test originated at work, response to recall tended to be poor. Of the non-returners 42%, but only 24% of the returners, had found the first test unpleasant or embarrassing. One-third of non-returners claimed difficulties in finding time, which is in accord with the lower response from full-time workers. Over 90% of those interviewed gave fear or modesty as the reasons why other women had not had a repeat smear. In general, differences in response to a letter inviting women to have a repeat smear are unlike those which characterize recruitment for a first smear. Consistency of experience appears to be strongly favoured in the regular use of cytological screening.


Migraine in general practitioners.

Migraine in general practitioners. A self-administerd questionnaire was posted to 1 129 medical general practitioners in an urban and in a rural area of England. The prevalences of headache, and of the features of migraine, in the year immediately preceding the survey were similar in the two areas. After allowing for the different age and sex composition of the populations, these prevalences were also similar to those found in the general population during an early survey in Wales. About 13% of the male and 25% of the female general practitioners thought that they had had migraine in the previous year. There was little evidence that doctors with 'classic' migraine differed from those with 'common' migraine in the proportion who experienced other migrainous features (unilateral distribution of headache and accompanying nausea) or in their response to treatment with ergotamine.


The deployment of home nurses.

The deployment of home nurses. A study in Derbyshire showed that there are wide variations in the populations served by individual home nurses. These variations are difficult to reduce. To assess the quantity and quality of home nursing that is provided more sophisticated formulae than the nurse/population ratio are necessary. For these data derived from output of work are inadequate; studies of need are required in each locality.


Deoxycytidylate deaminase in pregnancy.

Deoxycytidylate deaminase in pregnancy. Deoxycytidylate (DCMP) deaminase was assayed at various times during and after normal and abnormal pregnancies. The level in amniotic fluid was assessed at induction and at caesarean section, and cord blood levels were estimated after normal delivery and at caesarean section. A rise occurred during labour and after hysterectomy and caesarean section--returning to normal after 2-3, and 12 days respectively. Levels above 4.8 X 10-minus 4 ml-minus 1 were found in cases of preeclamptic toxaemia and early intrauterine death and in twin pregnancies over 36 weeks' gestation. It is suggested that because of its low incidence of false-negative and false-positive results this test is far superior to other enzyme tests in pregnancy, and a further trial is in progress to assess its role.


On the correlation of brain size and problem-solving behavior of ring doves and pigeons. The behavior of 12 adult ring doves [a small-brained species of Columbidae] was compared with that of 12 adult pigeons [a large-brained species of Columbidae] in a detour problem to see if Rensch's hypothesis of increased brain size being correlated with increased capability can be extended to a perceptual problem-solving task. Three detour dependent variables were intercorrelated with seven gross brain indices obtained from each bird. There were no species differences in terms of detour behavior, and no correlational trends of brain-behavior relationships were discernible. It was concluded that Rensch's hypothesis may not be generalizable to all types of behavior capabilities.


Structural and functional bases for frontal lobe participation in the organizationof complex behavior in cats. The differences in the cytoarchitectonic organization and the thalamocortical projections to the anterior and posterior cortical fields in cats provide the basis for judgements about their unequal roles in entire behavior acts. Extracellular recordings of anterior frontal neuronal activity have revealed the predominance of the nonspecific type of afferent activation of gyrus proreus neurons; complex integrative properties of gigantopyramidal neurones [posterior frontal regions] have been observed. Participation of the posterior frontal fields in afferent synthesis and in programming motor activity has been shown in behavioral studies. The phlogenetically younger anterior frontal fields are considered to be yet nonspecialized structures; posterior gigantopyramidal fields in cats are considered as the highest apparatus of programming complex motor activity in an experimental situation.


Scotopic and photopic visual capacitiesof an arboreal squirrel [ sciurus niger]. Behavior measurements of visualcapacities were made on fox squirrels [Sciurus niger.  Spectal sensitivity functionsmeasured in the context of an increment-threshold task reveal the presence of a Purkinjeshift in this species.  Under conditions of dark adaptation, the spectral sensitivityfunction is closely fit by a nomogram photpigment having a 500 nm maximum.  Under conditions of light adaptation, the spectral sensitivity function is bimodal in form with peaksat about 460 and 560 nm.  Several further tests of photopic visual capacity, althoughnot all entirely consistent in outcome, reveal that[a] these animals have color vision,[b] their color vision is not a normal trichromasy and, [c] only two underlyingphotopic components [with peaks at 450 and 540nm] are unmasked by chromatic-adaptationprocedures


Origins of anthropoid intelligence.

Origins of anthropoid intelligence. The development of the extrastriate visual system relative to the striate system was estimated indirectly by measuring the volumes of the lateral posteriorpulvinar complex and lateral geniculate nucleus in six varieties of mammals selected on the basis of their propinquity with Anthropoidea [oppossums, hedgehogs, rats, squirrels, tree shrews and bushbabies]. The same animals were tested on two related behavioral tasks [spatial and visual reversal learning] whose successful achievement requires a simple sort of abstraction. The results show that the ability to learn visual reversal, but not spatial reversal, corresponds closely to the relative degree of development of the extrastriate system. Since the variation in both these behavioral and morphological characteristics also parallels the phylogenetic dimension, the recency of common ancestry to anthropoids, the evolutionary origin of the anthropoid capacity for visual abstraction is suggested.


The effects of muting lesions on emotional behaviour and behaviour normally associated with calling. Bilateral intercollicular lesions in the chick abolish or depress not only calling, but also those phases of behaviour when calling would have been occurring. These include: long bouts of excited feeding immediately after food is made available; examining and pecking moving targets and novel objects; persistent scanning, and inhibition of other behaviour in a novel environment. Deaf birds behave precisely like controls, so that possible auditory deficits are not involved. During calling phases significant visual stimuli are treated as if they were starting or conspicuous. Conversely, continuous examination of a stimulus causes calling to diminish or disappear even though response continues; a brief period when the stimulus is not seen causes calling to begin again when it is once more perceived. In addition to the increased effectiveness of relevant visual stimuli, motor facilitation is usual in calling phases, as is inhibition of irrelevant responses. Emotional behaviour in man and other mammals is compared to calling phases in the chick.


Heat vasodilatation of the rat tail.

Heat vasodilatation of the rat tail. The vasomotor response of the tail of the albino rat to total-body heating and cooling was studied by skin-temperature recording and plethysmography with the tail at 25 degrees C air temperature. Tail vasodilation started at core temperatures lightly above 37 degrees C and increased to a core temperature up to about 39 degrees C. During cooling of warm rats, tail vasoconstriction started at significantly higher levels of core temperature than the values at which vasodilation appeared when the rat was warmed.


Cardiovascular response to glucagon in hypovolemic dogs. Glucagon in a dose of 50 mug/kg body weight was studied for its cardiovascular effects in hypovolemic dogs in which coronary blood flow was reduced to an average 40% of its control value and cardiac depression was evident. Myocardial contractility, as judged mainly by dP/dt and acceleration of aortic blood flow, was brought to a normal level for a short time. Systemic and coronary vascular resistances were markedly reduced. These effects were similar in normovolemic dogs. The inotropic, chronotropic, and peripheral vascular effects of glucagon can be evoked also in hypovolemic dogs in which coronary blood flow is less than normal and myocardial metabolism is impaired.


The insulinotropic action of gastric inhibitory polypeptide. The effect of highly purified gastric inhibitory polypeptide (GIP) on immunoreactive insulin (IRI) secretion in the conscious fasted dog was investigated. Significant increases in IRI release were observed with intravenous administration of three different doses of GIP. These were accompanied by depression in fasting serum-glucose levels. Preliminary studies were undertaken to determine whether this insulinotropic action of GIP could be attributed to a particular segment of the GIP molecule. GIP fragments produced by cleavage with cyanogen bromide and trypsin showed no significant stimulation of IRI release. The possibility that GIP might itself enhance glucose uptake or potentiate insulin-induced glucose uptake was studied with the rat hemidiaphragm preparation. No such effect was observed. In the light of this and other recent work, it is concluded that GIP is a strong candidate for an active principle in the enteroinsular axis.


Physical factors influencing fluid reabsorption from Henle's loop. Our objective was to produce reductions in the luminal volume of Henle's loop and increases in linear flow velocity through the loop. We did this in a recollection micropuncture study by collecting fluid with and without suction from early distal tubules. With suction, transit time of fast green dye through the loop decreased by 34%, calculated loop volume decreased by 28%, and fractional water reabsorption fell from 73.6 to 70.3% (p smaller than 0.025) in water diuretic rats. Absolute water reabsorption did not decrease significantly. In urea-saline dieuretic rats transit time decreased 25%, calculated loop volume decreased 22%, fractional reabsorption fell from 59.0 to 51.7% (smaller than 0.001), and absolute reabsorption decreased by 2.3 nl/min (p smaller than 0.025). Single nephron glomerular filtration rate, distal tubular sodium concentration, and osmolality were unaffected. The less pronounced effect of collection with suction in water diuretic rats may be related to the lower medullary fluid osmolality, which was 338 plus or minus 9 (S.E.) mOsmol/kg as compared to 497 plus or minus 35 in urea saline diuretic rats. Collecting fluid with suction from late proximal tubules did not alter glomerular filtration rate or fractional water reabsorption. Stumpe et al. ((1970) J. Clin. Invest. 49, 1200-1212) noted an inverse correlation between fluid reabsorption from Henle's loop and flow velocity in rats with hypertension or congestive heart failure. One can reproduce this correlation by artificially altering the transmural pressure gradient in the loop.


The inhibitory effects of prostaglandin E1 on guinea-pig ureter. Prostaglandin E1 (PGE1) hyperpolarized the smooth muscle cells of guinea-pig ureter in normal Krebs solution and was without effect on ureters depolarized in KCl Krebs, PGE1 inhibited both electrically induced contractions and K+-induced contractures of the ureters. Conditions that favored greater tension development by the ureters, namely, high [K+] or high [Ca-2+] reduced the inhibitory effects of PGE1 on the K+-induced contractures. Depolarization of guinea-pig ureter with KCl Krebs led to an increase in radio-calcium content of the tissue over a 30 min loading period. This increase in the tissue's radio-calcium content was further increased by PGE1 but not by theophylline, PGE1 was found to have no effect on either total calcium content or the calcium efflux from the tissue. It is suggested that PGE1 exerts its inhibitory action by increasing calcium sequestration at the inner surface of the cell membrane.


Divergent effects of excess dietary vitamin A on alimentary cholesterolemia in cockerels of different genetic backgrounds. The variable effect of excessive vitamin A intake on alimentary cholesterolemia was investigated in cockerels of strains of White Leghorns and New Hampshires. With the New Hampshire cockerels, the feeding of 0.5% of dietary cholesterol resulted in greater cholesterolemia when the diet contained 1700 I.U. of vitamin A per kilogram than when it contained 22000 I.U. of vitamin A per kilogram. With the White Leghorn cockerels, on the other hand, cholesterolemia was enhanced with the higher level of dietary vitamin A. Absorption of a single oral dose of cholesterol was increased in birds of both breeds when vitamin A had been given previously by injection. In the White Leghorn cockerels the percentage of newly absorbed cholesterol in the hepatic pool was reduced by vitamin A administration, whereas in the New Hampshire cockerels the percentage was increased. It was concluded that excess vitamin A may have divergent effects on alimentary cholesterolemia in chickens of different genetic backgrounds as a result of opposite effects on the liver-blood ratio of a large load of cholesterol.


Effects of local anesthetics and hemicholinium-3 on 45-Ca efflux in barnacle muscle fibers. Benzocaine, which occurs in the uncharged form in the physiological range of pH, caused inhibition of 45-Ca efflux in branacle muscle fibers. By contrast, in the presence of a low external Ca-2+ concentration it produced stimulation of the efflux. Both the inhibitory and stimulatory actions of benzocaine appeared to be less potent than those of procaine. Hemicholinium-3 (HC-3), on the other hand, which exists only in the charged form, caused a large stimulation of the 45-Ca efflux following microinjection, and the potency of this action was found to be at least 10 times greater than that of procaine. External application of HC-3 produced inhibition occasionally. Effects of tetracaine were similar to those produced by procaine; however, its inhibitory action was greater in more alkaline solution, which is the opposite of that observed with procaine. Lidocaine produced a less consistent effect than procaine; the inhibitory action of the former was less potent but the stimulatory action of the two anesthetics were comparable, p-Aminobenzoic acid was without effect on 45-Ca efflux. These results indicate that both the charged and uncharged forms of local anesthetics are capable of causing stimulatory and inhibitory effects on 45-Ca efflux in barnacle muscle fibers, and that the inhibition produced is the result of action on the CA-Ca exchange system whereas the stimulation is the result of release of Ca from internal storage sites.


Thermal, metabolic, and cardiovascular responses to various degrees of cold stress. The metabolic, thermal, and cardiovascular responses of two male Caucasians to 1 2 h exposure to ambient temperature ranging between 28 degrees C and 5 degrees C were studied and related to the respective ambient temperatures. The metabolic heat production increased linearly with decreasing ambient temperature, where heat production (kcal times m- minus 2 times h- minus 1) = minus 2.79 Ta  degrees C + 103.4, r = -0.97, P smaller than 0.001. During all exposures below 28 degrees C, the rate of decrease in mean skin temperature (Tsk) was found to be an exponential function dependent upon the ambient temperature (Ta) and the time of exposure. Reestablishment of Tsk steady state occurred at 90-120 min of exposure, and the time needed to attain steady state was linearly related to decreasing Ta. The net result was that a constant ratio of 1.5 of the external thermal gradient to the internal thermal gradient was obtained, and at all experimental temperatures, the whole body heat transfer coefficient remained constant. Cardiac output was inversely related to decreasing Ta, where cardiac output (Q) = minus 0.25 Ta degrees C + 14.0, r = minus 0.92, P smaller than 0.01. However, the primary reason for the increased Q, the stroke output, was also described as a third-order polynomial, although the increasing stroke volume throughout the Ta range (28-5 degrees C) was linearly related to decreasing ambients. The non-linear response of this parameter which occurred at 20 degrees C larger than or equal to Ta larger than or equal to 10 degrees C suggested that the organism's cardiac output response was an integration of the depressed heart rate response and the increasing stroke output at these temperatures.


Effect of chronic intake of ethanol on lactate/pyruvate and beta-hydroxybutyrate/acetoacetate ratios in rat liver. Adult male rats were fed a liquid diet providing 35% of the calories as ethanol, while pair-fed controls received the corresponding diet with alcohol replaced by an equicaloric concentration of sucrose. After 1 month, lactate/pyruvate (L/P) and beta-hydroxybutyrate/acetoacetate (beta-HB/AcAc) ratios in the livers were determined under five different conditions: (1) both diets present up to the time of sacrifice, (2) ethanol diet replaced by control diet for 24 h before sacrifice, (3) ethanol diet replaced by control diet for 48 h before sacrifice, (4) as in the preceding, followed by intraperitoneal (i.p.) injection  of ethanol, 1 g/kg, 1 h before sacrifice, (5) as in the preceding, but i.p. injection 3 h before sacrifice. The L/P ratio was significantly higher in the alcohol group than in controls under the first experimental condition, but the groups did not differ under the other four conditions. The beta-HB/AcAc ratio was also significantly higher in the alcohol group under the first condition. This difference disappeared in the second and third conditions. Under the fourth and fifth conditions the beta-HB/AcAc ratio was significantly higher in the controls. The results are compatible with an adaptive increase in mitochondrial reoxidation of NADH in the chronic alcohol groups, but the possibility of a change due to alcohol withdrawal can not be excluded.


Effect of a chronic suboptimal intake of magnesium on magnesium and calcium content of bone and on bone strength of the rat. Sprague-Dawley rats were kept at 28 degrees C from 21 to 517 days age and fed one of the two following diets: a semi-purified diet containing 502 p.p.m. of Mg (control) or the same diet containing only 120 p.p.m. (mg/kg) (low-Mg). The chronic suboptimal intake of Mg by rats fed the low-Mg diet did not result in overt signs of Mg deficiency even when Mg levels were greatly reduced in carcass, plasma, and tibia, but it significantly decreased bone strength. It is suggested that Mg deficiency in man could be a factor in the weakening of bone, commonly observed in old age, even when there are no visible signs of Mg deficiency. Studies of the human situation would be of interest.


Phosphate uptake into organic compounds in skeletal muscle. Isolated intact frog muscles were incubated in 32-P-labelled Ringer's solution for various periods of time (30 s-20 h). Labelled compounds were isolated from TCA, methanol-chloroform-water, and water extracts of muscle. Hexosephosphates, phosphocreatine, phosphoenolphyruvate, alpha-glycerol phosphate, adenosine triphosphate, and inorganic phosphate were identified after 30 s, and 4 h incubation. Much more labelling was found after 20 h. The incorporation of 32-P in 30 s into organic phosphate compounds, such as alpha-glycerol phosphate and ATP, showed that immediate esterification of Pi occured on, or just inside, the sarcolemma.


Effect of central cholinergic blockade on the hyperthermia evoked by prostaglandin E1 injected into the rostral hypothalamus of the rat. The possibility of a cholinergic involvement in the hyperthermic action produced by the injection of prostaglandin E1 (PGE1) into the anterior hypothalamic/preoptic region of the rat brain was examined. Intracerebral injection of either atropine or mecamylamine prior to the injection of PGE1 failed to attenuate the PGE1-induced hyperthermia. Both atropine and mecamylamine by themselves produced a rise in colonic temperature. It thus seems unlikely that PGE1 evokes hyperthermia in the rat by releasing endogenous acetylcholine at muscarinic or nicotinic synapses in the rostral hypothalamus. The possibility that PGE1 acts by inhibiting the release of acetylcholine within this region requires additional investigation.


Prophylaxis of recurring urinary tract infection in females: a comparison of nitrofurantoin with trimethoprim-sulfamethoxazole. Twenty-eight females with recurrent urinary tract infection were treated to eradicate their existing infections and then observed for recurrences while receiving one of the three following prophylactic regimens for 6 to 12 months: nitrofurantoin, 50 mg daily; one half tablet of trimethoprim-sulfamethoxazole (TMP-SMX) twice weekly; or one tablet of TMP-SMX once weekly. Preadolescent girls received half the adult doses. After completion of the course of prophylactic agent the patients were followed up at bimonthly intervals until infection recurred. After eradication of this new infection they were started on another prophylactic regimen. Six infections (1.0/patient-year) recurred in patients on nitrofurantoin, four infections (0.4/patients-year) reucrred in those receiving twice weekly TMP-SMX, and 12 infections (1.3/patient-year) in those receiving once weekly TMP-SMX. The mean interval between discontinuation of prophylaxis and recurrence of infection was 2.6 months. TMP-SMX in the doses used eliminated aerobic gram-negative rods from swabs from the anal canal in many patients. Gram-negative organisms resistant to trimethoprim did not cause infection either during or after therapy.


Maternal and transplacental kinetics of trimethoprim and sulfamethoxazole, separately and in combination. The fate of trimethoprim and sulfamethoxazole and the combination of both these agents was studied in a group of healthy pregnant women who were undergoing therapeutic abortion. Assays were performed on samples of blood, urine, amniotic fluid and fetal tissues, using a standardized protocol for the selection of patients, dose administration, sample collection and assay techniques. A comparative evaluation of kinetics to assess the maternal handling and the distribution of trimethoprim throughout the fetoplacental unit disclosed no significant difference in the concentration within fetal fluids and tissue compartments. On the other hand, the concentration of sulfamethoxazole was lower in fetal tissues than in fetal fluids when relative ratios to trimethoprim were compared. The implications of the difference in behaviour of pharmacokinetic and clinical points of view.


Effect of trimethoprim-sulfamethoxazole on blood insulin and glucose concentrations of diabetics. Trimethoprim-sulfamethoxazole (TMP-SMX) caused no significant changes in the blood glucose or insulin concentrations of diabetic subjects treated by dietary measures alone or by insulin and diet. In only one of eight subjects receiving oral hypoglycemic agents for the control of diabetes did a significant immediate increase in immunoreactive insulin follow administration of TMP-SMX. In the same patient hypoglycemic symptoms were present after the agent had been taken for 14 days.


Use of high-dosage trimethoprim-sulfamethoxazole in sinusitis. The combination trimethoprim-sulfamethoxazole was given in high dosage (four tablets twice daily) for either 2 or 5 days to 20 patients with sinusitis diagnosed on clinical grounds. In 11 the infection was improved or cured. Swabs cultured from 18 patients of the series produced no growth in 8. The organisms most likely to be isolated are Hemophilus influenzae and Diplococcus pneumoniae.


Trimethoprim-sulfamethoxazole in chronic bronchitis. Authenic tracheobronchial secretions/exudates (TBSE) were aspirated under direct vision via a sterile catheter passed through a fiberoptic bronchoscope from patients with chronic obstructive pulmonary disease complicated by chronic bronchitis. TBSE, saliva and blood were obtained during long-term administration of trimethoprim-sulfamethoxazole (TMP-SMX) and were assayed for drug content. Before and during treatment TBSE were cultured qualitatively and quantitatively for aerobic and anaerobic bacteria, fungi, mycoplasmas and viruses. Treatment with TMP-SMX was associated with a decrease in the recovery of Hemophilus influenzae, H. parainfluenzae, Klebsiella pneumoniae, Escherichia coli and Proteus mirabilis; however, little effect was observed on the typically nonpathogenic aerobic and anaerobic bacteria of the upper respiratory tract. TMP was found in saliva at concentrations greater than in serum. Both TMP and SMX entered TBSE in absolute and relative concentrations sufficient to take advantage of the potential for synergy against susceptible microorganisms. Patient tolerance of TMP-SMX was generally good and several patients reported a decrease in production of sputum during treatment.


Four isomeric ethyl 1-thioglycosides from 2-amino-2-deoxy-D-arabinose. Ethyl 2-amino-2-deoxy-1-thio-alpha- and -beta-D-arabinopyranoside (2 and 4) were obtained by direct ethanethiolation of 2-amino-2-deoxy-D-arabinose (1), and their structures were determined by mass and p.m.r. spectrometry. Ethyl 2-amino-2-deoxy-1-thio-alpha- and -beta-D-arabinofuranoside (11 and 13) were prepared by partial demercaptalation of 2-amino-2-deoxy-D-arabinose diethyl dithioacetal (6) with mercuric chloride (or, preferably, with bromine), with or without protection of the 5-hydroxyl group. Demercaptalation with mercuric chloride gave the beta-D anomers almost exclusively, and treatment with bromine gave a mixture of the alpha and beta anomer in the ratio of similar to 1:1. Alternatively, direct ethanethiolation of 1 in trifluoracetic acid yielded the alpha-D anomer. The structures of 11 and 13 were determined by mass spectrometry, by direct comparison of their N-acetyl derivatives with an authentic enantiomorph (15b), and by p.m.r. spectroscopy. The physicochemical properties of the four 1-thioglycosides (2,4,11, and 13) were compared with those of the O-GLYCOSIDES of D-arabinose.


Calcium binding to D-glucuronate residues: crystal structure of a hydrated calcium bromide salt of D-glucuronic acid. Three-dimensional X-ray diffraction data were used to determine the crystal structure of alpha-D-glucuronate CaBr times 3H20, a model system for investigating the factors involved in the binding of calcium ions to D-glucuronate residues of oligo-and poly-saccharides. Crystals of the salt are monoclinic, space group P21, having a = 6.410 (1), b = 10.784 (2), c = 8.879 (1) A, betta = 92.07 (1)degrees, and Z = 2. Instensity data for 1082 reflections were measured with an automated diffractometer. A trial structure, obtained by the heavy-atom method, was refined by least squares to R = 0.025. The absolute configuration was confirmed by anomalous-dispersion effects. An outstanding feature of the crystal packing is the interaction of D-glucuronate anions with calcium ions. The calcium ion is coordinated to three symmetry-related D-glucuronate anions and to two water molecules. The D-glucuronate anion binds calcium cations through three chelation sites: one that involves a carboxyl-oxygen atom combined with O-5; one that includes the second carboxyl-oxygen atom acting in concert with O-4, and one composed of the O-1-O-2 pair of hydroxyl groups.


Water sorption in a dextran gel.

Water sorption in a dextran gel. The state of adsorbed water in a dextran gel has been investigated by near-infrared gravimetric-adsoprtion techniques. Water-vapor adsorption (desorption) isotherms at three temperatures are reported. The calculated sorption heats are found to be markedly temperature-dependent as well as dependent on the coverage. The near-infrared spectrum (4650-9000 cm-minus 1) is reported, together with tentative assignments. The H2O combination (v+delta) band at 5184 cm-minus 1 has been examined as a function of relative humidity. The line-shapes of this band have been analyzed by a recently established, Fourier-inversion technique, and information on the microdynamics of the absorbed water molecules has been resolved on the picosecond time-scale. At low and intermediate degrees of hydration, reorientational jumps take place with periods from four to six times longer than those for free water. The onset of saturation is then accompanied by the sudden removal of the reorientational jumps. A comparison of microdynamical and thermodynamic data indicates the hydration mechanism to be highly cooperative at all relative humidities.


Graded-hydrolysis studies on bael (Aegle marmelos) gum. Graded hydrolysis of purified bael gum afforded three neutral and two acidic oligosaccharides, together with monosaccharides. These sugars were identified through periodate oxidation, methylation, reduction with lithium aluminum hydride, co-chromatography, and preparation of crystalline derivatives. The neutral oligosaccharides were characterized as 3-0-beta-D-galactopyranosyl-L-arabinose, 5-0-beta-D-galactopyranosyl-L-arabinose, and 3-0-beta-D-galactopyranosyl-D-galactose, and the acidic oligosaccharides as 3-0-(beta-D-galactopyranosyluronic acid)-D-galactose and 3-0-(beta-D-galactopyranosyluronic acid)-3-0-beta-D-galactopyranosyl-D-galactose.


The use of cellulose xanthate for the immobilisation of biological molecules. The mercapto groups of cellulose xanthate can reversibly form disulphide bridges with L-cysteine. This property has been utilised for the immobilisation of a protein and an enzyme. These macromolecules, as polythiol derivatives, formed disulphide linkages with the matrix without serious disturbance of their active sites, became firmly bound to the xanthate, and were not eluted by normal washing conditions. Cellulose xanthate is a cheap, easily prepared matrix which permits a simple coupling reaction. The immobilisation process is selectively reversible.


Modification of polysaccharides containing uronic acid residues. Klebsiella Type 47 capsular polysaccharide has side chains attached to the main chain via D-glucuronic acid residues. The side chains have been removed to yield an essentially linear polysaccharide by the following sequence of reactions: (1) substitution of hydroxyl and carboxyl groups with methyl vinyl ether; (2) beta-elimination by treatment with base; (3) removal of modified uronic acid residues and protecting groups by mild acid hydrolysis. The possibility of modifying other uronic acid-containing polysaccharides by this method is discussed.


Identification of O-cetylated N-acylneuraminic acids by mass spectrometry. A number of O-acetylated N-acylneuraminic acids, isolated from submandibular glands of cow and horse and from horse erythrocytes, have been characterized by mass spectrometry. On the basis of the typical fragmentation patterns of the pertrimethylsilyl derivatives of the methyl esters of the compounds, they were identified as 4-O-acetyl-, 9-O-acetyl-, 4,9-di-O-acetyl-, and 7,9-di-O-acetyl N-acetylneuraminic acid, and 4-O-acetyl-and 9-O-acetyl-N-glycolylneuraminic acid.


Complexation of reducing and nonreducing carbohydrates with hydroxides of some alkali and alkaline-earth metals. Complexation of D-arabinose, D-fructose, D-glucitol, D-glucose, D-mannitol, L-sorbose, D-xylose, sucrose, and amylose with LiOH, NaOH, KOH, Ba(OH)2, Ca(OH)2, and Sr(OH)2 has been studied conductometrically. D-Glucitol and D-mannitol do not bind with any of the bases used. Molecular complexes (1:1) of the other carbohydrates are formed in solution. Reducing sugars bind more strongly than nonreducing ones. Stability constants for the complexes have been determined; the free-energy change is of the order of hydrogen bonding. The association process has been observed to depend significantly on the polarity of the medium.


Cell growth and thymidine incorporation changes induced by Dolichos lectin in embryo fibroblasts at various stages of differentiation. We report here the effect of Dolichos lectin on chick embryo fibroblasts from embryos between 6th and 16th day of development. There is evidence that Dolichos lectin decreases cell number and proportion of cells incorporating tritium labelled thymidine in case of chick embryo fibroblasts of 6th, 8th and 10th day of development. Dolichos lectin stimulated the proliferation of 16-day old embryo cells. No effect was noticed on 12-day embryo cells at different concentrations of Dolichos lectin used. This lectin is specifically inhibited by N-acetyl-D-galactosamine and anti-Dolichos lectin serum. The difference in response by cells during different stages of embryonic development could perhaps be explained as some regulatory changes occurring on the cell surface.


Amoeba proteus: the nuclear periphery.

Amoeba proteus: the nuclear periphery. This study extends previous work on the nuclear envelope and associated structures. It illustrates that the cylindrical structures of the honeycomb lattice are not attached to the nuclear envelope, although generally perpendicular and closely apposed to it, and that there is a complex arrangement of fibrillar material between the cylinders of the lattice. The relationship of nuclear helices to these structures is described and the possible mode of their transfer from nucleus to cytoplasm is discussed.


The hemoglobins of the developing chicken embryos. Fractionation and globin composition of the individual component of total erythrocytes and of a single erythrocyte type. The hemoglobins of the chicken embryo at several stages of development have been isolated in pure form by column chromatography and their relative amounts and globin compositions determined. The analyses on separated primitive and definitive erythrocytes show that the first contain four hemoglobins different from the adult ones. The two  major ones at four days, decrease gradually and are no longer detectable from 15 days on. The two minor ones increase up to 6-7 days, then decrease but are still present at hatching. The definitive embryonic erythrocytes contain two hemoglobins identical to the adult ones but their ratios change gradually during development and approach that of the adult hemoglobins at hatching.


Immunological measurement of transferrin compared with chemical measurement of total iron-binding capacity. Because of uncertainty as to the molecular weight of transferrin, a previous comparison [Von der Heul et al., Clin. Chim. Acta 38, 347 (1972)] between transferrin content of serum and total iron-binding capacity cannot be definitive. We found a conversion factor for expressing the maximum amount of iron bound by 1 mg of transferrin. We compared the resulting calculated value with values obtained by three other methods for measuring total iron-binding capacity. We agree with the previous observation that the latter, as measured radioisotopically, give higher results than would be judged from the transferrin content but the same as those for two chemical methods. The diffusion rate of transferrin in agar was the same irrespective of the degree of iron saturation. Serum transferrin concentrations were low in patients with anemia resulting from malignancy, chronic disorders, and cirrhosis of the liver, and high or normal in patients with iron deficiency anemia and in pregnant women or women who were taking birth-control pills. Measurement of transferrin concentration can be used to distinguish iron deficiency anemia from anemia resulting from chronic disorders, but offers no advantages over existing methods for estimating total iron-binding capacity.


Electrophoretic patterns of alkaline phosphatase isoenzymes in human sera with abnormally high activity, and an unusual band observed in sera of patients with pancreatic cancer. Alkaline phosphatase isoenzymes in sera were resolved by electrophoresis on cellulose acetate membranes into seven different bands (L1, B, Pl, L2, l1, l2, and Pa, in decreasing order of electrophoretic mobility). The slowest moving band (Pa) was observed in the sera of 16 patients--15 with cancer of the pancreas and one with hemochromatosis. Sera of 50 other patients with malignant or benign diseases did not show the Pa band. The Pa band is more heat labile than is the liver isoenzyme (L1). Its behavior toward inhibitors (L-phenylalanine and L-homoarginine) is similar to that of L1. Sera containing the Pa band exhibit a diffuse band in the region where isoenzymes of intestinal origin migrate; however, its heat stability and sterospecific inhibition are different from those of intestinal isoenzymes in sera that show no Pa band.


Comparison of electrophoresis on citrate agar, cellulose acetate, or starch for hemoglobin identification. We compare and discuss three electrophoretic methods for identifying hemoglobins S, A, C, F, and D or G. Electrophoresis on citrate agar gel was more sensitive than electrophoresis on cellulose acetate for detecting hemoglobins S and F, a fundamental consideration in designing cord-blood screening programs for detecting hemoglobin S carriers. Electrophoresis on starch gel is evidently an acceptable method for subtyping hemoglobins AA, CC, AS, SS, AC, and SC, and is more sensitive than cellulose acetate for identifying hemoglobin A1A2. Costs for the citrate agar gel, cellulose acetate, and starch gel procedures are presented.


Aspartate aminotransferase and alanine aminotransferase activities in plasma: statistical distributions, individual variations, and reference values. The determination of frequency value (percentile limits) and the classification of the different variation factors allow us to define more and more homogeneous subpopulations as we use these factors for sorting. Using as our study population those persons coming to the Centre for Preventive Medicine, we were able to: (a) Describe and measure the significance and importance of physiological variations or of variations attributed to age--the latter largely related only to excessive weight, which it seems to us is often the case. (b) Establish a classification for variation factors; the recapitulatory table should be useful to clinical chemists in helping physicians interpret a laboratory test result that falls within the zone of incertitude. (c) Suggest a preliminary group of reference values for healthy subjects, to be used in interpreting a laboratory test in this way.


Detection of cardiac-specific creatine kinase isoenzyme in sera with normal or slightly increased total creatine kinase activity. We describe a spectrophotometric kinetic assay for detecting creatine kinase MB isoenzyme activity in the 1 to 10 U/liter range. The MB isoenzyme was isolated [Clin. Chem. 20, 36 (1974)] and assayed (Rosalki method) with an Abbott ABA-100. Good reproducibility was demonstrated for MB isoenzyme activities near 1 U/liter (CV = 2.6%). Sera with normal or slightly increased total creatine kinase activity were evaluated. Sera of 14 patients with acute myocardial infarction contained, per liter, 84 to 236 U of total creatine kinase activity and 4.6 to 28.0 U of isoenzyme MB activity; corresponding ranges for sera from healthy lab technicians and patients with noncardiac disease were 36 to 277 and 0 to 2.6 U. MB isoenzyme activity for infarction patients rose and fell sharply within three days after the infarction. Atypical time-course patterns, MB isoenzyme activity remaining abnormally great for five days, were observed in serum from patients with prolonged atrial fibrillation and congestive heart failure or cardiomyopathy; the BB isoenzyme (1 to 5 U/liter) was also detected in sera of such patients but was absent in sera from infarcation patients. Quantification of column-isolated MB by the assay described is rapid, easy, specific, and extremely sensitive for measuring MB in the 1 to 10 U/liter range.


Simultaneous separation of serum creatine kinase and lactate dehydrogenase isoenzymes by ion-exchange column chromatography. Lactate dehydrogenase isoenzymes were partially separated by use of a previously described column technique for creatine kinase [Clin. Chem. 20, 36 (1974)]. Extracts of lactate dehydrogenase-rich tissues were used to evaluate column resolution. Samples layered on mini-columns containing DEAE-Sephadex were eluted with Tris-buffered sodium chloride (100 and 200 mmol/liter). Lactate dehydrogenase activity in column effluents was measured by the Wacker method, and their isoenzyme content was assessed by electrophoresis on polyacrylamide gel. Dehydrogenase isoenzymes 3, 4, and 5 were separated from isoenzymes 1 and 2, and the separation was tissue-specific and reproducible. The electrophoretic technique for isoenzymes 3, 4, and 5 gave values about 20% lower than did the column technique. Sera from 15 healthy laboratory technicians contained total lactate dehydrogenase, isoenzymes 1 and 2, and isoenzymes 3, 4, and 5 in the ranges 94 to 152, 34 to 64, and 38 to 75 U/liter, respectively. Activities of sera from 15 patients with acute myocardial infarction (total lactate dehydrogenase) ranged from 212 to 800 U/liter and lactate dehydrogenase isoenzymes 1 and 2 ranged from 138 to 628 U/liter. Lactate dehydrogenase and creatine kinase isoenzymes were rapidly and easily measured after being simultaneously separated. The procedure is specific and sensitive for following the post-infarct time course of changes in isoenzyme activities.


Evaluation of the Beckman "System TR enzyme Analyzer". We evaluated 16 claims made by Beckman Instruments, Inc. for its Enzyme Analyzer (System TR), under a rigid written protocol for the Product Evaluation Subcommittee of the Standards Committee of the College of American Pathologists. We found the following to be within the company's specifications: (a) accuracy and precision of the temperature control; (b) accuracy and precision of the sample and reagent pipets; (c) instrument precision, both within-run and between-day; (d) carry-over from a sample with activity greater than 1000 U/liter; (e) instrument-to-instrument variation; (f) analytical linearity; (g) analysis time; (h) correlation of the instrument-printed answer with the activity calculated manually from a strip-chart recorder; (i) precision of the instrument's built-in electronic "standard"; (j) effectiveness of the over-range indicators; and (k) correlation between results of these enzyme assay methods and those for kinetic methods used in our laboratory. The instrument performed well.


Practical applications of radioimmunoassay theory. A simple procedure yielding linear calibration curves. The fundamental equation describing radioimmunoassays under equilibrium conditions has been recast into a "working equation" in a form more directly applicable to the requirements of the analytical laboratory. Plotting total counts over counts bound vs. ligand concentration, which is conveniently linear over most of its course, is shown readily to yield quantitative data relative to binding site concentration and the equilibrium constant and to provide a means for deriving apparent labeled ligand concentration. Such data are helpful in establishing optimum assay conditions and can serve a continuing quality-control function. The working equation also characterizes the binder and tracer reagents used in the assay. The determination of working-equation parameters has been illustrated for the vitamin B-12 assay. Data are presented for seven different assay procedures, involving more than 600 calibration curves and 100 different lots of binding agent and tracer reagent, showing a consistently high correlation coefficient (r greater than 0.990), between ligand concentration and the response variable.


Erythrocyte protoporphyrin in the detection of iron deficiency. Any decrease in the availability of iron for incorporation into the heme moieties of hemoglobin results in an increase in the erythrocyte protoporphyrin concentration. Our aim was to compare protoporphyrin concentrations, determined spectrophotometrically, with body iron stores, as assessed from the amount of iron demonstrable by Prussian blue staining of bone marrow aspirates. The mean protoporphyrin concentration (175 mu-g/dl) in the erythrocytes of a group of patients with markedly decreased stainable marrow iron or no iron was significantly greater (P less than .001) than the mean concentration (76 mu-g/dl) in a comparable group with adequate bone marrow iron stores, except in the presence of certain interfering conditions. These results suggest that the erythrocyte protoporphyrin test may be a useful addition to the methods now available for assessing disorders of heme synthesis, the most common of which is iron deficiency.


Electrophoretic method for assessing the normal and pathological distribution of alkaline phosphatase isoenzymes in serum. We describe a simple, reproducible, discontinuous system for polyacrylamide disc gel-electrophoresis, with which the alkaline phosphatase isoenzymes in human serum can be fractionated. No sample preparation is needed. The isoenzymes are classified according to their electrophoretic mobilities (R-F values) and quantitated by peak area measurements from spectrophotometric scans. The four alkaline phosphatase isoenzymes usually present in normal sera, in order of descending mobilities (and designated according to principal tissue of origin) are: "fast" liver, "slow" liver, bone, and intestine. Sera of diseased patients show a greater variety of isoenzyme distribution patterns, but the most frequently observed patterns are the same as normal patterns. We conclude that the finding of "fast" liver only is not pathognomonic, as previously reported by others, and that information on relative distributions per se is not diagnostically useful, although information on specific increases in activity is useful. With this system, hepatobiliary disorders can be differentiated from other forms of liver and bone diseases.


New Colorimetric reaction for end-point, continuous-flow, and kinetic measurement of urea. A reaction of urea, o-phthalaldehyde and N-(1-naphthyl)ethylenediamine is described for measurement of urea by manual, continuous-flow, and kinetic methods. The continuous-flow system requires 25 mu-l of sample; 40 samples can be analyzed per hour. The kinetic method requires no enzymes, has no lag phase, and has good sensitivity. A major advantage of the reaction is that it occurs at a temperature of 37 degrees C or lower. The results obtained by all three methods agree well with those for a continuous-flow procedure in which diacetyl is a reagent.


Interlaboratory proficiency, intermethod comparison, and calibrator suitability in assay of serum aspartate aminotransferase activity. Sources of variation in assays of aspartate aminotransferase (EC 2.6.1.1) activity were examined in an interlaboratory survey and through an examination of materials used as calibration materials in these assays. Four highly stable lyophilized specimens containing human cytoplasmic enzyme, with activities of 0, 22, 46, and 96 U/liter at 30 degrees C and optimal substrate concentrations, were assayed by 319 laboratories. Mean values obtained on these specimens by laboratories using 2,4-dinitrophenylhydrazine kits varied among manufacturers and deviated from values expected from this procedure. The average coefficient of variation (CV) with these kits was greater than 20%. Automated continuous-flow procedures with use of diazonium salt showed the best precision (av CV, less than 10%). However, the automated continuous-flow malate dehydrogenase/NADH coupled method produced an average CV greater than 20%. Results from each of the automated methods were related to a reference malate dehydrogenase/NADH coupled continuous kinetic assay method by temperature relationships alone. Mean values from manual diazonium salt procedures were 1.7-fold greater than similar reference values (av CV was 18%). The higher results were attributed to the use of poorly-defined units and to an artifact caused by chromophore stabilizers in this procedure when aqueous samples are used. The average CV in continuous kinetic methods varied among kit manufacturers, ranging from 6 to 28% for the specimen of highest activity. Variations in results were much larger at 366 nm than at 340 nm than at 340ity. Variations in results were much larger at 366 nm than at 340 nm. Interassay relationships of these methods are presented. Concentrations of pyruvate in commercially available calibration  materials differed between manufacturers, varied in stability, and deviated from the expected concentration. For some colorimetric assays the precision attained on reported absorbance values for the enzyme specimens was of the same order of magnitude as that for pyruvate standards. Other sources of error are revealed by the interlaboratory survey. The value of commercially available sources of enzyme activity as calibration or control materials was assessed by evaluating the following properties: activity at suboptimal concentrations of L-aspartate or 2-oxoglutarate, temperature effects, preincubation lability owing to aspartate and phosphate, pyridoxal phosphate saturation, contamination with glutamate dehydrogenase, and manufacturer's rated activity. These properties are compared to those of human cytoplasmic enzyme in a human serum matrix.